I explained at the head of this thread how and why Xen works in thismanner. It's certainly a change from native execution; whether youconsider it to be a bug is a different matter.

But it turns out that leaving stray mappings around on pages which getlater used in special ways is a bad idea, and can manifest in all kindsof random unpleasant ways. Getting a clear error out of Xen is probablynicest way to discover and debug this problem.